Piston



June 2, 1925.

C. F. OBERACKER PISTON Filed May 20, 1924 2 Sheets-Sheet l Paiemedlune 2, 1925.

UNITED sTATEs CLARENCE l'. OBERACKEB, 0F CLEVELAND, 0R10.

PISTON.

Applicaties med lay ao, 1924,' serial no. 114,607.

To all whom it may concern:

Be it known that I, CLARENCE F. OBER- ACKER, a citizen of the United States, residing at Cleveland, in the coun-ty of Cuyahoga and State of Ollio, have invented certain new and useful Improvements in a Piston, of which the following is a specification.

This invention relates to new and useful improvements in pistons which are principally adapted for use in connection with the cylinders of internal combustionengines and has for its principal object to provide a simple and etlicient device which will fit properly in the cylinder so as to operate therein eiiiciently.

A further object of the invention is to provide a pistonl construction of the above mentioned character. wherein the skirt of the piston is' provided with an irregular slit whereby to provide for the expansion of the piston to conform to the size of cylinder in which the same is to operate, the provision of the irregular slit being to overcome the tendency of the skirt of the piston to wear on one side or crawl as is customary with tile pistons now in use having a straight s it.

A still further objectv of the invention is to provide a piston of the above mentioned character, wherein means is associated therewith for causing oil which is forced up 1n the cylinder into the piston to be received in suitable oil pockets provided in the outer face of the piston and from which oil may be lcaused to flow around the outer walls of the piston in suitable oil grooves provided therefor thus lubricating the piston for the purposes well known in the art.

A further object to the invention 1s to provide a piston construction of thev above mentionedcharacter. which is simple in construction.' inexpensive, strong and durable and ,furthermore adapted for the purposes for which itis designated.

Other objects yand advantages of this invention will become apparent during the course of the following description.

Inthe accompanying drawing forming a part of this specification, and in which like numerals designate like parts throughout the' same,

Figure 1 is a side elevation ofmy improved piston,

Figure 2 vis a similar view showing the op site sides thereof, u

igure 3 isa vertical section therethrough,

Figure 4' is a bottom plan view of the piston, and

Figure 5 is a transverse section taken approximately on line 5-5 of Figure 1,-looking in the direction of the arrows.

In the drawings wherein for the purpose of illustration is shown thepreferred embodiment of my invention, the numeral 1 designates generally my piston, and the same comprises the head portion 2 and the skirt portion 3. Arranged on opposite sides of the skirt 3 of the piston 1 are the usual Wrist pin receiving openings 4 and the outer face of the skirt around each of the openings 4 is cut away as shown at 5 in the drawing to provide a substantially keystone shaped `oil.pocket on each side of the skirt 3 in which the openings 4 are provided in theV manner clearly illustrated in Figure 1 of the drawings. Extending around the outer face of the skirt portion 3 of the piston 1 and arranged in horizontal spaced relation are the oil grooves 6. The majority of the oil grooves are adapted to communicate with the oil pockets 5 inthe manner also clearly illustrated in Figure 1 of the drawings.

Providedin the outerwall of the head.

section 2 of the piston 1, are the usual piston ring grooves 7 in which are adapted to be seated in the well ltnwn manner the piston rings- (not shown). The head section 2 is further provided with a reinforcing rib 8 on the under face thereof in the manner also clearly illustrated in the drawings.

Provided in the lower portion of the oilv pockets 5 are t-he horizontally extending slots or openings 9, and the purpose thereof,

will be presently described. Suitable baille plates such as are illustrated atl() in the drawings with reference more particularly to Figure 3 are formed integrally with the skirt of the piston and extend inwardly from. the upper edges of the slots 9 for a suitable distance. The baille plates '10 rovide a means for causing the oil whic is forced upwardly intothe piston to be directed outwardly through the openings 9 so that` the same may be receivedV in the oil pockets 5 in -the manner as willbe hereinafter more fully described. Formed in the upper. portion of the skirt 3 below the piston ring grooves 7 are the diametrically 0pposed slots 11 and the same are arranged between the wrist pin openingsl in the manner as clearly illustrated in Figures 1 and 2 of thel drawings.

' vided therein.

-upper portion of the skirt in the manner clearly illustrated in Figure 3 of the drawings, and as is clearly illustrated, the lower portion of theirregular slot 12 is disposed at an angle to the upper portion of the slot, thepurpose of this construction is to provide for an even and equalized expansion of the piston with respect to the cylinder in which the same is supported, thereby preventing the uneven wearing of the piston and further preventing the crawling of one portion of the iston adjacent the slit proprovided with a substantially vertical straight slit in the skirt portion thereof and the piston with a construction of this character has a tendency to wear unevenlycausing the uneven expansion of the skirt portion and thus reducing the length of time which a piston may be used for efficient operation.

IVhen the piston is in position within the cylinder of an internalcombustion engine, a portion of the oil `from the crank case will be forced upwardly into the cylinder and piston and the oil passing into the piston will strike the baffle plates 10 and will be directed outwardly through the openings or slots 9 so that the same will be caused to flow into the oil pockets 5 arranged around each of the wrist pin openings 4. The oil from the pockets 5 will flow into the oil grooves 6, thus properly lubricating ,the walls of the cylinder in which the piston operates for the purposes well known in the art. Further, the slots 11 provided in the upper portion of the skirt will have a certain quantity of oil passed therethrough and the oil passing therethrough will be caused to cooperate with the piston ring grooves to lubricate the same and thereby prevent the possibility of the piston rings from freezing or otherwise sticking in the piston ring grooves. If desired, a suitable channel such as is shown at 13, in Figure 3 in the drawings, may be provided for supplying-a quantity of oil to the wrist -pin bearings supported in the openings 4.

It will thus be seen from the foregoing description, that a piston has been provided which is simple in construction, strong andv eretofore pistons have been durable and very inexpensive and the parts are so arranged as to insure the proper h1- brication of the walls of the cylinder in which the piston is adapted to operate. Furthermore the provision of the irregular slots in the skirt portion of the piston permits the expansion of the piston to the proper diameter of the cylinder thereby assuring the etiicient operation of the piston and preventing any possibility of the uneven expansion of the skirt of the piston.

IVhile I have shown the preferred embodiment of my invention-` it is to be understood that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention and the scope of the appended claims.

Having thus described the invention, what I claim is 1. A piston comprising a head and skirt portion. said head portion having piston ring grooves provided therein, av reinforcing rib formed on the under face of the head portion, `the outer faces of the skirt portion around the wrist pin openings provided therein being cut away -to provide diametricall)v opposed oil pockets, said skirt portion having annular oil grooves extending around the outer face thereof and communicating with said oil pockets, the lower portions of the oil pockets having slots provided therein to receive oil passing upwardly into said piston. and means for directing the oil into said slots.

2, A piston comprising a head and skirt portion, said head portion having piston ring grooves provided therein, a reinforcing rib formed on the under face of the head portion, the outer faces of the skirt portion around the wrist pin openings provided therein being cut away to provide diametrically opposed oil pockets, said skirt portion havlng annular oil grooves extending around the outer face thereof and communicating with said oil pockets, the lower portions of the oil pockets having slots provided` therein to receive oil passing upwardly into said piston, means for directing the oil int-0 said slots, said means comprising bafiie plates formed integrally with the skirt portion and extending inwardly from the upper edges of said slots.

In testimony whereof I affix my signature.

CLARENCE oBERAoEn.

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